When the Sun is high overhead, the sky towards the zenith is a much darker blue, while the sky towards the horizon is a lighter, brighter cyan color. This is due to the larger amount of atmosphere, and the larger amount of scattered light, that is visible at low angles on the sky. Image credit: Karsten Kettermann / Pixabay.

“In the media age, everybody was famous for 15 minutes. In the Wikipedia age, everybody can be an expert in five minutes. Special bonus: You can edit your own entry to make yourself seem even smarter.” ―Stephen Colbert

It’s been another fun-and-fact-filled week here at Starts With A Bang! (And did you know I have a wikipedia page? I do! And most of the facts there are even correct!) I’m planning out the next edition of the Starts With A Bang podcast, which should cover the science that the James Webb Space Telescope will reveal starting in just over a year; yes, we’re just 13 months from launch! We’re also looking into starting a video series, with the financial (and idea-filled) help of our generous Patreon supporters, as well as some exciting interviews coming up in advance of the October 15th release of Treknology, which should take the world by storm! Now, let’s have a look back at all our article from this past week:

The fabric of spacetime, illustrated, with ripples and deformations due to mass. A new theory must be more than identical to General Relativity; it must make novel, distinct predictions. Image credit: European Gravitational Observatory, Lionel BRET/EUROLIOS.

From Elle H.C. on Einstein’s opinion on the aether: “To quote Einstein:

“We may say that according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an aether. According to the general theory of relativity space without aether is unthinkable; for in such space there not only would be no propagation of light, but also no possibility of existence for standards of space and time (measuring-rods and clocks), nor therefore any space-time intervals in the physical sense. But this aether may not be thought of as endowed with the quality characteristic of ponderable media, as consisting of parts which may be tracked through time. The idea of motion may not be applied to it.”

The scientific community has ruled against Einstein on this topic…”

It’s not so much that “the scientific community” made a ruling as it is that Einstein’s “unthinkable” interpretation was actually equivalent to his own interpretation. If you call the mathematical structure of “spacetime” an “aether,” I can’t really say anything to change your mind, but you are redefining words to make the “aether” exist. If that were the case, let me turn it around on you: what would an aether-less spacetime look like?

The conventional thinking is that when we talk about empty space — the “vacuum” — we are talking about what we physically know as nothingness itself. This is what contains the entire Universe. Nothing more is required. You can certainly invent something more (or something else), but unless it has a physical difference from the predictions of nothingness itself, it doesn’t have a physical meaning.

The quantum wavefunction, and the potential for quantum tunneling through a finite barrier. Image credit: Chi LF collaboration, from John von Neumann Institut fur Computing.

From eric on the spreading of quantum wavefunctions: “Many (I want to say ‘all’ but I’m not sure about that) wavefunctions are much larger than what we would consider the discrete particle to be. The photon is, in reality, ‘smeared out’ over a much larger area.”

The important thing to remember is that wavefunctions are not static entities, but rather that they spread out over time! There is an uncertainty inherent to anything’s position and momentum, and so that means that if you know where something is and how it’s moving at any particular moment in time, even to an accuracy of Planck’s constant, there is an uncertainty that grows with time and distance as far as where this particle will be in the future. So if you take the extrema of the possibilities and allow that sort of spreading, it’s pretty impossible to not have some portion of the wavefunction wind up a seemingly absurd distance away.

The only way out is to make a high-energy-enough measurement to collapse the wavefunction, which is where the “quantum zeno’s paradox” comes in, and why a watched radioactive atom doesn’t decay the same as one that you simply leave alone.

From Steve Blackband on a book recommendation: “Highly recommend Rise of the Rocket Girls by Nathalia Holt. An easy holiday read, [focusing] on the efforts of the women ‘computers’ in the space program, much like the book by Dava Sobel called the Glass Universe [focusing] on the women who read astronomy photographic plates.”

I haven’t come across this book, so I’m very curious to learn about it! For anyone interested in the history of both the space program and the role that women in science have played, it gets good reviews from people I respect. Pick up a copy at Amazon here.

Reactor nuclear experimental RA-6 (Republica Argentina 6), en marcha. As long as there’s the right nuclear fuel present, along with control rods and the proper type of water inside, energy can be generated with only 1/100,000th the fuel of conventional, fossil-fuel reactors. Image credit: Centro Atomico Bariloche, via Pieck Darío.

From Sinisa Lazarek about whether Einstein is always a good authority about physics: “Well, Einstein also said: “There is not the slightest indication that nuclear energy will ever be obtainable. It would mean that the atom would have to be shattered at will.”

Just because someone made great contribution in one area, doesn’t make him absolutely correct about everything.”

It goes beyond that, actually. Just because someone is an expert and made a great contribution in one area doesn’t mean they are correct about everything they say even in that area. Alan Guth was the inventor and originator of inflation, yet his original model was untenable and everyone knew it. Fred Hoyle made tremendous strides in uncovering the properties of the primordial light in the Universe yet would not accept that his model for departures from a blackbody spectrum did not fit the observations. Einstein was not only wrong about many aspects of quantum and nuclear physics (despite winning a Nobel for the photoelectric effect), but made many mistakes concerning relativity, including the declaration that gravitational waves were a physical impossibility.

The idea that “one should listen to the master” is absurd; you should listen to the correct argument that is made for the correct reasons, regardless of who makes it. Einstein was wrong. A lot. So was pretty much every scientist in history. We must tread carefully here, and not fall for the fallacy of picking the quotes and statements that support what we want reality to be.

Placing a chunk of sodium metal in contact with water results in a violent, and often explosive, reaction. Image credit: Wikimedia Commons user Tavoromann.

From John on whether science describes or explains: “One of the unresolved, and possibly unresolvable, tensions in Science – in the instance Physics – is whether it describes or explains. As seen above, some are firmly (even emphatically) members of the descriptive camp. I found Ethan’s “What’s the quantum reason that sodium and water react?” (05-AUG-17) a delightful example of Science’s – in that instance physical Chemistry – ability to explain.”

I think this is an interesting topic to consider. The sodium-and-water example feels like a good explanation, rather than merely a description, because we have a deep understanding of what physics underlies it. If you ask “why do the quantum energy levels behave as they do,” you’re likely to come away with more of what feels like a description than an explanation, even though those quantum energy levels are what power the sodium-and-water reaction. If we have a deeper layer (or two, or more) of understanding than what you’re asking about, it’s easier to explain what’s going on. But if you’re at that deepest level that humanity has ever gone, usually it only feels descriptive.

At that most fundamental level, I don’t know that it’s possible to do any better.

This cutaway showcases the various regions of the surface and interior of the Sun, including the core, which is where nuclear fusion occurs. Although hydrogen is converted into helium, the majority of reactions, and the majority of the energy that powers the Sun, comes from other sources. Image credit: Wikimedia Commons user Kelvinsong.

From Frank on the brightness of the Sun’s center: “All cutaway views of sun I had seen show its center as the brightest region. But I think if we could really see inside of sun almost all of it would look black. Because I think visible light is produced close to the surface. Am I right on this?”

You know, I was all prepared to write to you about blackbody spectra, the energy produced, how collisions between gamma-ray photons and particles in the Sun’s core produce thermalization and a very hot, intense set of radiation that spans the full electromagnetic spectrum, and so on. I was prepared to show you images like this:

And to tell you that being hotter meant more radiation of all wavelengths, so long as you obey that blackbody law. And then I saw, just below, that Candice Elliot has beaten me to it, providing an excellent explanation.

This is one of those Berkelian questions… since we can’t actually do a cut-away. However, no, the region inside of the core would still be amazingly hot and does radiate in the visible region… but that most of the energy in the core is radiating at high energies up into the gamma. So, it would still be bright in the visible. You might want to look up ‘black body radiation’. As the temperature goes up, the energy peak goes up (shorter wavelength/higher energy per photon)… but so does the amount of energy in non-peak wavelengths.

As the energy passes from the convention zone to the surface, the volume of the mass that is available goes up so the temp goes down and at the very surface, the temp cools such that the peak is now in the visible range (of course it is! That’s because we evolved to use the peak range to see!)

So, good job! In short, the core of the Sun would be brighter than the core of any cooler blackbody, all other things being equal, no matter which wavelength of light you looked at. Remember, hotter objects contain more energy overall, and that affects what you “see,” among a myriad of other things!

The Eagle Creek fire has now spread to engulf over 10,000 acres, has caused the evacuations of thousands of families, and millions of dollars in property damage. The terrain itself will take decades to recover. Image credit: Tristan Fortsch/KATU-TV via AP.

From Ragtag Media on the cause of wildfires: “Or rather The Terrifying Actions Of Environmentalist Cause Disaster.
Thank a Spotted Owl”

What many people on both sides of the political aisle — including those on the far right who blame environmentalism for hampering the logging industry and those who blame the logging industry for destroying America’s natural resources — don’t realize is how many strides have been made in the practice of sustainable logging over the years. All the major logging companies, like Weyerhauser (which dominates where I live), now treat lumber as a crop. You cut a portion, you replant, you let it grow, you harvest, etc. This is how it works, it’s good for the environment, etc.

However, there are a great many compelling reasons to think that we have not yet arrived at the ideal fire, wildlife, flora-and-fauna management system. For protected lands like forests, natural fires do occur. Should we clear out the underbrush? If so, by how much? Should we engage in controlled burns? Of what magnitude? These are questions still being discussed today, and they should still be discussed. There is much to still learn.

With that said, I would hope that everyone here would be against arson. Would be against throwing fireworks into the woods when there’s a burn ban. And would be against the 80% of wildfires that are caused by human negligence and/or malice. My wife and I had our lives endangered by one that was started atop Powell Butte a few years ago just outside of Portland, OR, by… a group of teenagers. We were the first to call 911 and alert them. We were out hiking and had to race back to our car and leave. We got out, but… I mean, come on. It’s okay to say, “arson is bad,” and to call irresponsible fire-starting exactly what it is: arson.

“Well, it would seem prudent that the first and best line of defense is for humans to stop setting wildfires.”

Image credit: Andrew Walsh, aka flickr user radiofree.

From MobiusKlein on the culture wars: “Not every science discussion needs to start with a Culture War rerun.”

The cynical part of me wants to say, “have you been on the internet before?”

But I think this is a good place to bring something up about forest management that’s very important. A lot of people focus on the “renewing” effect that burns have, clearing out the old, dead brush and allowing the ecosystem to start over. Because of human activity, a lot of what will first grow when we have a wildfire, will be invasive species. If they take root in the early stages, they can choke out the natural habitat which would have grown there if not for the introduction of these species by human activity.

If we want to restore the natural habitat after a wildfire occurs, in many locations (like in the Columbia Gorge), we absolutely need human intervention to properly manage the restoration. This is a big part of what the forest service does, and will be doing in the coming months after the fires are put out.

This is a Digitized Sky Survey image of the oldest star with a well-determined age in our galaxy. The ageing star, catalogued as HD 140283, lies over 190 light-years away. The NASA/ESA Hubble Space Telescope was used to narrow the measurement uncertainty on the star’s distance, and this helped to refine the calculation of a more precise age of 14.5 billion years (plus or minus 800 million years). Image credit: Digitized Sky Survey (DSS), STScI/AURA, Palomar/Caltech, and UKSTU/AAO.

From Carl on how a star appears older than the age of the Universe: “Two words: stellar progeria.”

Certainly, if the star actually does appear to be 14.5 billion years old, something must’ve happened to cause that “artificially large” age we ascribe to it. But what was it? For the last word of the week, Omega Centauri has an idea:

“What if the star originally had a brown dwarf companion, and was a bit lower in mass early on then would appear to make sense today? So say after a few billion years, it merged with its brown dwarf gaining a few percent of mass.”

The globular cluster Messier 5, shown here in this NASA/ESA Hubble Space Telescope image, is one of the oldest belonging to the Milky Way. The majority of its stars formed more than 12 billion years ago, but there are some unexpected newcomers on the scene, adding some vitality to this aging population. These blue stragglers resulted from mergers of smaller stars, and create larger, apparently younger ones. Image credit: ESA / Hubble & NASA.

This actually goes the wrong way; this would make a star appear younger than it actually is, akin to blue stragglers. What would work is for something to have stripped a bit of the mass away from the star. If you can have a more massive star age, burn through its fuel, and then lose some of its mass, it will evolve more quickly. Even if that’s the case, the big question is how. Off the top of my head, my first idea is that this star began in a globular cluster or a multi-star system, was the less-massive companion in a binary (or more) system, it had some of its mass siphoned off after billions of years, and then a close gravitational interaction with another body ejected it into the galaxy, away from its former companions, where we observe it today.

But I have no evidence for this. The Universe is like a detective story with insufficient clues. Until we catch another, similar star doing something as compelling as this, we don’t know whether this explanation is possible. Regardless, we can only see the survivors in the Universe today, and infer what might have (or must have) happened in the past. The rest is why this is such a great cosmic puzzle!

See you back here next week for more exciting stories of science and the Universe here on Starts With A Bang!

“One of the unresolved, and possibly unresolvable, tensions in Science – in the instance Physics – is whether it describes or explains.

I’m wondering if this is nothing more than a semantic issue; English having multiple words for what is, in practical terms, the same outcome. We do science to gain information, and then we use that information to do other things; accomplish human social or policy goals. Are there any activities that can be accomplished by ‘explain’ science that can’t be accomplished by ‘describe’ science? Is mere ‘describe science’ unable to cure cancer? Launch satellites?

I think, in fact, that science accomplishes the same activities, contributes to society the same ways, regardless of whether you call it explanatory or merely descriptive.

Ethan in reply to Elle HC:
” If you call the mathematical structure of “spacetime” an “aether,” I can’t really say anything to change your mind, but you are redefining words to make the “aether” exist. If that were the case, let me turn it around on you: what would an aether-less spacetime look like?”

“The conventional thinking is that when we talk about empty space — the “vacuum” — we are talking about what we physically know as nothingness itself. This is what contains the entire Universe. Nothing more is required. You can certainly invent something more (or something else), but unless it has a physical difference from the predictions of nothingness itself, it doesn’t have a physical meaning.”

So… back to “spacetime” as “nothingness itself”:
Yet “mass tells IT how to curve and IT tells mass how to move”(conventionally speaking, as per Wheeler.)

IT is a “mathematical structure.” IT is “nothingness itself.” Yet IT functions as a malleable medium (aether?) The “science” of GR theory doesn’t even ask how that mechanically happens in the world to which the “mathematical structure” refers… if there is one (according to instrumentalists) existing independent of man’s math and models!

So… “You can certainly invent something more (ed: and call it “spacetime”)… but it doesn’t have a physical meaning.”

Such is the nature of “spacetime”… even as it curves around masses like the Sun and guides the planets in their orbits!

Or it could just be the force of gravity “acting at a distance” (god forbid!)… Maybe via the (as yet unconfirmed) Higgs Field filling all space… no longer the vacuum of “nothingness.”

“It’s not so much that “the scientific community” made a ruling as it is that Einstein’s “unthinkable” interpretation was actually equivalent to his own interpretation.”

No, that doesn’t make sense. This is more like it:

“The Copenhagen Interpretation denies that the wave function provides a directly apprehensible image of an ordinary material body or a discernible component of some such, or anything more than a theoretical concept.

In metaphysical terms, the Copenhagen interpretation views quantum mechanics as providing knowledge of phenomena, but not as pointing to ‘really existing objects’, which it regarded as residues of ordinary intuition. This makes it an epistemic theory. This may be contrasted with Einstein’s view, that physics should look for ‘really existing objects’, making itself an ontic theory.” – https://en.wikipedia.org/wiki/Copenhagen_interpretation#Metaphysics_of_the_wave_function

—

“what would an aether-less spacetime look like?”

That’s not the right question, SpaceTime is only a mathematical framework it isn’t Space itself.

Space itself can’t exists exist without an æther. It would be like a ocean without water. You need a medium for waves to travel and things to come to life.

“The sodium-and-water example feels like a good explanation, rather than merely a description, because we have a deep understanding of what physics underlies it. If you ask “why do the quantum energy levels behave as they do,” you’re likely to come away with more of what feels like a description than an explanation, even though those quantum energy levels are what power the sodium-and-water reaction. If we have a deeper layer (or two, or more) of understanding than what you’re asking about, it’s easier to explain what’s going on. But if you’re at that deepest level that humanity has ever gone, usually it only feels descriptive.”

As you seem to remain persuaded that a description of a process or an event is equivalent to an explanation for the process or event, by all means enjoy your conviction. It is, as you’re aware, not an opinion I embrace.

I hope you can accept that there can be, and are other valid opinions.

As your posts suggest to me that your position is that the sodium and water example does not count as an example, please explain why you think the underlying physics provided by Ethan do not produce an explanation, and provide a contrasting example of what you consider a real example.

Absent that, I suggest acknowledging that reasonable people can disagree, and agree to disagree about the equivalence of the terms “explanation” and “description”.

In re needing “anything deeper in this case”, as the question was “What’s the quantum reason that sodium and water react?”, the answer is no. Ethan provided the explanation.

What many people on both sides of the political aisle — including those on the far right who blame environmentalism for hampering the logging industry and those who blame the logging industry for destroying America’s natural resources — don’t realize is how many strides have been made in the practice of sustainable logging over the years. All the major logging companies, like Weyerhauser (which dominates where I live), now treat lumber as a crop. You cut a portion, you replant, you let it grow, you harvest, etc. This is how it works, it’s good for the environment, etc.
However, there are a great many compelling reasons to think that we have not yet arrived at the ideal fire, wildlife, flora-and-fauna management system. For protected lands like forests, natural fires do occur. Should we clear out the underbrush? If so, by how much? Should we engage in controlled burns? Of what magnitude? These are questions still being discussed today, and they should still be discussed. There is much to still learn.

All true. It’s also true that the people who still make blanket unsupportable accusations of blame against “radical environmentalists” are ignoring, intentionally or from lack of knowledge, the fact that huge fires destroyed massive amounts of land during the height of the logging years in the Midwest: Alpena, Manistee, Holland, and the Port Huron region had massive fires in 1871, the same time as the terrible fire in Peshtigo Wisconsin. A great deal of the “thumb” area in Michigan burned in 1881. These weren’t the consequences of ‘radical environmentalists”.

Summary: people who use the term “radical environmentalists” aren’t concerned with facts, only political agenda.

As your posts suggest to me that your position is that the sodium and water example does not count as an example, please explain why you think the underlying physics provided by Ethan do not produce an explanation

No you misunderstand me. I’m happy to count it as an explanation if that is your argument. I’m trying to understand what YOU THINK is the difference.

I’m actually okay with Ethan’s definition; when there are deeper layers of understanding we can point to, we’ll call it an ‘explanation.’ When there aren’t, we’ll call it a ‘description.’ Its somewhat subjective (which is why I think it’s somewhat semantic) if you are okay with it too we can reach agreement?

You should know the answer to that question because you say that ‘mainstream’ scientists are liars, so we all expect you to know how it works. So please tell us how does gravity works, scientifically speaking, what makes the apple fall?

All GR does is describing the relationships of how a massive element affects its surroundings (Space) and in which frame, it does this very well, but what the underlying ‘forces’ are that’s not something GR/SpaceTime tells us, that’s something an Aether theory could help us with, explaining what it is that fills Space and make GR happen.

In the paper, ‘An overview is given of what mathematical physics can currently say about the vacuum state for relativistic quantum field theories on Minkowski space.’

You can write papers about waves and currents of the ocean without talking about H2O. In CFD you can use Boltzmann or Navier–Stokes equations etc. you don’t ‘need’ water just like you don’t need an aether in Space Time to do your calculations.

But as Einstein said, ““According to the general theory of relativity space without aether is unthinkable”; it’s as if he says that GR predicts an aether. He’s pointing to search beyond GR and look what Space is made of.

Referring to your comment (#2, 10-SEP-17), “I’m wondering if this is nothing more than a semantic issue …” indicates that the list of acceptable responses includes only those that are limited to assessments of semantic content. When I hear or read someone taking a position that the differences between alternatives is “nothing more than a semantic issue”, it is usually within a context in which that individual considers the differences small and inconsequential, slight and insignificant, almost needing no serious discussion.

Having nothing else available as evidence to judge the meaning of your words, and reading you question about the language, (#6, 10-SEP-17) “Okay, can you give me an example of both? Preferably an example relevant to science.” I offered a dictionary reference to the definition of the words (#9, 10-SEP-17) you and I share and which discriminates between them.

Your question (#12, 10-SEP-17), “So you’re saying the sodium and water example counts as an explanation?”, followed by “You don’t think we need anything deeper in this case?” added more weight to the idea that you viewed the dictionary definition and my distinction between “description” and “explanation”, was at best, trifling.

I had then, do now, and expect in the future to think that a description (e.g. “The sky is blue.”) is qualitatively different from an explanation (e.g. “The reason the sky is blue is because …”).

The good news is that when I hear or read someone taking a position that the difference between alternatives is “somewhat semantic”, it usually occurs in a context in which that individual accepts that the differences are significant and substantial, while also remarking that the borders between them are linguistically porous; where the one bleeds into the other without a clear demarcation. This later situation is common, and if that position is indeed yours, then we now share a mutual understanding.

In closing, the better news (#17, 11-SEP-17) is “I’m actually okay with Ethan’s definition; when there are deeper layers of understanding we can point to, we’ll call it an ‘explanation.’”, although I think it differs from your position expressed at comment #12.

See #19. So there is NO EXPLANATION of what “spacetime” is (“nothingness itself?”) or how IT is “curved” or how IT “guides” the movement of masses. Yet mainstream science (including Ethan) constantly insists that it is in fact a malleable and mass-guiding medium, even though it is really “nothing” but a geometric math model. What physical world? Who cares anyway what it is, if anything, as long as the math works? I do.

Let me try to compare the situation with gravity to a clock. And lets i.e. imagine that it’s a digital clock. And let’s say you don’t actually know what a watch is or how it works… but you see numbers appearing in a certain way, and you notice patterns… and if you’re smart, you can write a perfectly solid and precise model and predict when a certain number will appear on the display. You have no idea how the inner workings of a digital watch work (in this hypothetical situation), no idea about electrons, or IC’s or anything else. Until you actually tear it apart and find out. Even without “knowing” how it works, you know when the something will happen, you have a predictive model. So this is the case with our current knowledge of gravity. We know how it will work in pretty much any place in the universe. We don’t know how it will behave in most extreme scenarios, like plank scales or highest energy levels. Our best theory tells us what will happen and why, it doesn’t currently tells us how that actually happens. Yes, in some other areas of physics, we have a more deeper understandings of the actual underlying processes. But not yet for gravity… and there are host of other areas.. CP violation i.e. just from top of my head.

Nothing to whine about “NO EXPLANATION”. Well, sorry for the human race not being omniscient at this time.

SL, You missed a piece:
Yet mainstream science (including Ethan) constantly insists that it is in fact a malleable and mass-guiding medium, even though it is also “nothing” but a geometric math model. Real science does investigate, describe and try to explain the real world of physical stuff and forces.

If you insist that IT is curved by mass and in turn IT guides the movement of masses, then IT must be something, not nothing. Unlike Ethan, I am committed to honesty in science.
Maybe the Higgs Field will become the new name for the (“non-existent”) aether… space filled with energy quanta connecting everything. That would be quantum physics’ replacement of GR’s “curved spacetime,” now (dishonestly) treated as an established fact.

Where do you get the idea that spacetime is regarded as “nothingness”? Science certainly does not promote that idea. There seems to be a confusion between terms like “vacuum” or “empty space” and the term “nothing”. The term “vacuum” or “empty space” can be defined simply as a region in which there is no matter. That does not imply that it is “nothing”. There are indeed quantum fields and virtual particles found in vacuum, so it cannot be “nothing”.

Once the distinction is made between “vacuum” and “nothing”, why is it so incredible to you that this vacuum can have the properties ascribed to it by GR? Why cannot vacuum be affected by the presence of nearby matter? Why is it that vacuum cannot affect the motion of matter?

The problem you have is conflating terms; it’s not necessarily a problem with your idea. (not that your idea is necessarily right; but I am not really qualified to definitively speak to that question). The term “aether” as it has been used historically in physics referred to something that is completely different from what you propose, something that HAS definitively been ruled out. The term aether was invented because Galilean relativity was well known by the time Maxwell worked out the full electromagnetic equations, and the alternative that actually turned out to be correct was so counterintuitive that nobody actually thought about it (until Einstein). Galilean relativity basically states that there is no such thing as the absolute velocity of anything. Statements like “the velocity of light is 3.0E8 m/s” are to be regarded as nonsensical. To make that statement sensible required a modification such as “the velocity of light relative to its medium of propagation is 3.0E8 m/s”. Maxwell’s equations made precisely the first statement. Since this was not acceptable, physicists modified it to the second one and used the term “aether” to refer to the medium through which light travelled.

This aether was considered a physical substance. All kinds of strange properties were ascribed to it based on the observed motion of light. It was held to be as rigid as steel, but easily passed through without noticing.

It was only once Einstein developed SR that the correct modification “light travels at a speed of 3.0E8 m/s with respect to all observers” was realized. That eliminated the need for the aether, and all of its strange properties. The idea that there is a field permeating all of space does not resurrect this idea of the aether. The aether had properties quite different from the Higgs field. Like I said, I am not qualified to discuss the viability of the idea that the Higgs field might be the cause of gravity. I do know, however, that the Higgs field is not identical to the old aether.

Sean T, #27:
“Where do you get the idea that spacetime is regarded as “nothingness”? Science certainly does not promote that idea.”

Ethan, quoted in #3 above (my caps):
“The conventional thinking is that when we talk about empty space — the “vacuum” — we are talking about what we physically know as NOTHINGNESS ITSELF. This is what contains the entire Universe. Nothing more is required. You can certainly invent something more (or something else), but unless it has a physical difference from the predictions of NOTHINGNESS ITSELF, it doesn’t have a physical meaning.”

Try to keep up with Ethan’s contradictions and presentation of theoretical conjecture as facts.

Elle: I think Sean’s point is that calling it an ‘aether’ would confuse it with an historical notion which it doesn’t resemble.

Do you remember an earlier post by me about the confusion caused by physicists naming properties the same words used by lay people to denote other things (like ‘spin’)? Lay people then try and analogize the technical concept to the common meaning of the word, with bad results.

Sure we could call it an aether and try and keep in mind that it’s not the same sort of aether that 19th century people were talking about. But IMO that would cause greater confusion, not greater understanding. 20th century spacetime and 19th century aether are not the same thing.